Remove function call logging

Log function calls is basically what a debugger does, and lot more. If
someone wants to know which functions are called, use gdb and add a
breakpoint at the call. That can be done conditionally too, and
attributes can be inspected.

Removed by coccinelle script:

@@
expression LVL;
expression FMT;
expression list VALS;
@@

- log_debug_info(DEBUGL_FUNCTIONS, LVL, FMT, VALS);

Signed-off-by: Max Sikström <msikstrom@op5.com>
Refactor service check scheduling

Always reschedule a service check one check_interval in the future
directly at event handler execution. If we want something closer,
replace the event, so we can guarantee that one service check event is
scheduled at all time. If we can do that, we know for sure that we
don't forget about service checks.

Signed-off-by: Max Sikstrom <msikstrom@op5.com>